Rayon yarns are obtained from

Nylon-$66$ is

Identify the polymer used in making floor tiles.

Phenol and formaldehyde undergo condensation to give a polymer $(A)$ which on heating with formaldehyde gives a thermosetting polymer $(B)$. Name the polymers. Write the reactions involved in the formation of $(A)$. What is the structural difference between the two polymers?

Ebonite is

$A$ polymer with high chemical stability has a melting point $(M.P.)$ of $327\ ^\circ C$ and the density of a completely crystalline sample is $2.3\ g/cm^3$. It is: